Closer Look: ASUS GTS 450 DirectCU TOP

As I mentioned in the intro, the ASUS ENGTS450 DirectCU TOP includes a number of non-reference features as well as the standard items you'd expect from a mid-range video card. We'll first take a look at the overall appearance of the card, the video ports it offers, and the DirectCU heatsink and fan unit. Then, with the heatsink off, we'll move into some of the more technical details as we take a closer look at the chip itself, the memory, and the power circuitry.

In the photo above, we get a good glimpse of the ENGTS450 as a whole. The fan and plastic shroud covering the heatsink are appropriately branded with the ASUS logo, but that's about as far as it goes--no full-length stickers or flashy graphics. I personally like the minimalist approach, but when graphics are done well, they look great as well. That said, I'm glad they went with a black PCB as it will match most of the motherboards out there. It's a bit hard to see in the photo, but they also include a metal bracket along the length of the PCB to provide additional rigidity and hold it level.

Turning out attention to the other side of the ENGTS450, we find the card's three display ports. HDMI, VGA, and DVI all come natively. I don't have much need for VGA these days, but there are those who may appreciate it. One thing definitely worth pointing out here, though, is the native HDMI support. The reference GTS 450 supports HDMI, but only has a mini connector. It's not a problem if you have a mini HDMI cable or the necessary adapter, but it's nice to have a full HDMI port built in. Of course, you give up the second DVI port to get it.

Another non-reference component is the heatsink and fan I mentioned earlier in the review. With it removed and cleaned off, it's clear why ASUS calls it DirectCU. Two copper heat pipes can be seen and are exposed directly to the GPU. ASUS claims that, as a result of this non-reference design, the entire heatsink and fan unit yields up to 20% lower temperatures during load and is up to 35% quieter while the card is idle. We won't be testing the sound level, but we will revisit the temperature claim a bit later in the review.

With the heatsink removed, we got our first look at the GF106 chip itself. The NVIDIA logo and a few other markings that got washed out in the light, but you can clearly see the die labeled with GF106-250-KA-A1. We discussed the architecture of the chip in detail on the previous page, so I won't go into detail here. What I do want to point out, though, are the clock speeds of our ENGTS450 TOP. The reference chip comes in at 783 MHz for the graphics clock and 1566 MHz for the CUDA cores. The ASUS card, on the other hand, manages 925 MHz and 1850 MHz, an 18% increase over stock--not bad for an extra $10.

So far, we haven't discussed the memory in much detail. As you can see, the chips are from Samsung, part number K4G10325FE-HC05. Each chip is 128MB and our card has eight for a total of 1024MB. The same chips can be found on the on the reference model, which runs them at 3608MHz. However, they're actually rated for 4000MHz, which what ASUS decided to set them at with the ENGTS450 TOP.

The last area where ASUS decided to up the ante is in the ENGTS450's VRM design. As you can see in the image above, they went with a four-phase approach and POSCAP capacitors (not pictured) to ensure adequate and stable voltage for overclocking. The voltage can be adjusted via ASUS' Smart Doctor software. With this Voltage Tweak technology, they claim that the consumer can achieve up to 50% faster performance. We'll, of course, put this claim to the test in our overclocking section.